358 NEW BOOKS. 



TRANSACTIONS OF SOCIETIES. 



South African Institute of Electrical Engineers. — Thursday, 

 March 27th: Mr. J. \V. Kirkland, President, in the chair. — "Motor con- 

 verters : their general characteristics and application in practice " : J. W. 

 Saaler. The author described and discussed the design of 3-phase and 

 2-phase converters, and made special reference to the practical working 

 of converters under the heads of synchronising force, voltage regulation, 

 commutation, three wire supply, reversibility, and efficiency. 



Thursday, April 17th: Mr. J. W. Kirkland, President, in the chair. — 

 " Mechanical defects in polyphase motors " : W. C. Brown. The principal 

 defects referred to were : vibration, resulting from the design of the slide 

 rails or from the machines being top-heavy; troubles with pulleys, either 

 resulting from their materials, or from their being keyed on to the shafts; 

 the loss of time and expense owing to the more powerful motors not 

 being supplied with split end shields and bearings ; the difficulties conse- 

 quent upon wear when motor-spindles have the same diameter throughout ; 

 and the insufficient provision of oil rings on bearings. 



Royal Society of South Africa. — Wednesday, May 21st : Dr. L. 

 Peringuey, D.Sc, F.E.S., F.Z.S., President, in the chair. — " Notes on 

 Ngamiland " : A. G. Stigand. A general account of Ngamiland and its 

 inhabitants. — " Some new South African mosses " : Prof. H. A. Wager. 

 — " Magnetic observations taken at Bloemfontein " : W. A. D. Rudge. 

 An account of the diurnal range of declination at Bloemfontein from 

 August to December, 1912. The mean value of the declination is about 

 24° \Y. The total change in declination has been as much as 10.8 minutes 

 in a day. The change in position of the maximum, and also of the range, 

 is of the same order as noted by General Sabine in the records taken at 

 Cape Town more than sixty years ago. — "Notes on the vertebral column 

 of the Bushman race in South Africa '' : Prof. R. B. Thomson. The 

 bodies of the cervical and thoracic vertebrae are relatively narrower in 

 their anterior-posterior diameter, and deeper in their vertical depth by 

 about 5 per cent, as compared with Europeans. 



Cape Chemical Society. — Friday, May 30th: Prof. R. Marloth, M.A., 

 Ph.D., President, in the chair. — " The present state of knowledge of South 

 African plants and plant products " ( Presidential address ) : Prof R. 

 Marloth. An account of chemical work done in connection with South 

 African indigenous plants, arranged in botanical order. Special refer- 

 ence was made to plants and parts of plants used for tanning, to fodder 

 plants and to medicinal and poisonous plants. 



NEW BOOKS. 



Gibson, J. Y. — The story of the Zulus: New ed. gin. X 6in. pp. vii., 358 



illus. London : Longmans, Green & Co., igir. 10s. 6d. 

 Rolin, Henri. — Les lots et l' administration de la Rhodesie. 8vo. pp. 



xlvii, ^2. Maps. Brussels: Emile Bruylant, igi3. 480Z., /r.15. 

 Brown, A. S. and G. G. — The Guide to South and East Africa. i2mo., 



pp. liv, 695. London : Sampson Low, Marston & Co., 1913. 240Z., 



is. 



Hansch, F. — Die Aufteilung Afrikas. pp. 27. Leipzig: B. G. Teubner, 

 1912. 302. 



